@Walaa Eldin Moustafa <wa.moust...@gmail.com>, for RexNodes there seems to be already this "generic return type visitor pattern" via RexVisitor; in fact, RexShuttle is just an implementation of RexVisitor.
On Thu, Dec 2, 2021 at 9:06 AM Walaa Eldin Moustafa <wa.moust...@gmail.com> wrote: > +1 while maintaining backward compatibility. Is there a plan for RexShuttle > too? > > On Thu, Dec 2, 2021 at 1:03 AM Ruben Q L <rube...@gmail.com> wrote: > > > Sounds like a good idea, as long as it does not break backwards > > compatibility. > > > > Regards, > > Ruben > > > > On Thu, Dec 2, 2021 at 7:22 AM Jay Narale <jaynarale3...@gmail.com> > wrote: > > > > > ＋1 re-writing to other types would be easier with this > > > > > > On Thu, Dec 2, 2021 at 16:18 Alessandro Solimando < > > > alessandro.solima...@gmail.com> wrote: > > > > > > > Hi Jacques, > > > > I have faced the same issue recently and I think it's a good idea to > > > have a > > > > generic version of it and have RelShuttle be one of its concrete > > > > implementations. > > > > > > > > Best regards, > > > > Alessandro > > > > > > > > > > > > Il Gio 2 Dic 2021, 06:02 Jacques Nadeau <jacq...@apache.org> ha > > scritto: > > > > > > > > > Right now, RelNode's accept method and RelShuttle forces a user to > > > return > > > > > RelNodes. This makes tree traversal/conversion extra painful in > main > > > > > circumstances (you want to have more specific relnode classes > > explicit, > > > > you > > > > > want to rewrite to non-relnodes, etc). I've worked around this for > > many > > > > > years but really think it should be resolved inside Calcite. I > wanted > > > to > > > > > get some feedback on introducing a more generic pattern (that > > > RelShuttle > > > > > becomes a concrete variation of). If people are on board with the > > > change, > > > > > I'll pull it through the codebase. > > > > > > > > > > You can see the rough idea in this wip patch: > > > > > https://github.com/apache/calcite/pull/2625 > > > > > > > > > > Basically, introduce a new parameterized visitor that people can > use. > > > > This > > > > > doesn't change the existing behavior of RelShuttle (it's now just a > > > > > specific version of this generic version) but it does allow other > > > rewrite > > > > > patterns. > > > > > > > > > > Thoughts? > > > > > > > > > > > > -- > > > Warm Regards, > > > > > > Jay Narale > > > > > >
